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author | Yong Wang <yong.y.wang@linux.intel.com> | 2009-05-29 13:28:35 +0800 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-05-29 09:04:58 +0200 |
commit | c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7 (patch) | |
tree | 4e674688eb9ba7a84ab34db4bf51cfca34edf6ed /arch/x86 | |
parent | da417a7537cbf4beb28a08a49adf915f2358040c (diff) | |
download | linux-stable-c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7.tar.gz linux-stable-c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7.tar.bz2 linux-stable-c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7.zip |
perf_counter/x86: Always use NMI for performance-monitoring interrupt
Always use NMI for performance-monitoring interrupt as there could be
racy situations if we switch between irq and nmi mode frequently.
Signed-off-by: Yong Wang <yong.y.wang@intel.com>
LKML-Reference: <20090529052835.GA13657@ywang-moblin2.bj.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/include/asm/perf_counter.h | 4 | ||||
-rw-r--r-- | arch/x86/kernel/apic/apic.c | 2 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/perf_counter.c | 19 |
3 files changed, 8 insertions, 17 deletions
diff --git a/arch/x86/include/asm/perf_counter.h b/arch/x86/include/asm/perf_counter.h index d08dd52cb8ff..876ed97147b3 100644 --- a/arch/x86/include/asm/perf_counter.h +++ b/arch/x86/include/asm/perf_counter.h @@ -91,10 +91,10 @@ extern void set_perf_counter_pending(void); #ifdef CONFIG_PERF_COUNTERS extern void init_hw_perf_counters(void); -extern void perf_counters_lapic_init(int nmi); +extern void perf_counters_lapic_init(void); #else static inline void init_hw_perf_counters(void) { } -static inline void perf_counters_lapic_init(int nmi) { } +static inline void perf_counters_lapic_init(void) { } #endif #endif /* _ASM_X86_PERF_COUNTER_H */ diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 89b63b5fad33..60df2efd7c80 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1135,7 +1135,7 @@ void __cpuinit setup_local_APIC(void) apic_write(APIC_ESR, 0); } #endif - perf_counters_lapic_init(0); + perf_counters_lapic_init(); preempt_disable(); diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index 2eeaa99add1c..316b0c995f38 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -604,7 +604,7 @@ try_generic: hwc->counter_base = x86_pmu.perfctr; } - perf_counters_lapic_init(hwc->nmi); + perf_counters_lapic_init(); x86_pmu.disable(hwc, idx); @@ -863,24 +863,15 @@ void set_perf_counter_pending(void) apic->send_IPI_self(LOCAL_PENDING_VECTOR); } -void perf_counters_lapic_init(int nmi) +void perf_counters_lapic_init(void) { - u32 apic_val; - if (!x86_pmu_initialized()) return; /* - * Enable the performance counter vector in the APIC LVT: + * Always use NMI for PMU */ - apic_val = apic_read(APIC_LVTERR); - - apic_write(APIC_LVTERR, apic_val | APIC_LVT_MASKED); - if (nmi) - apic_write(APIC_LVTPC, APIC_DM_NMI); - else - apic_write(APIC_LVTPC, LOCAL_PERF_VECTOR); - apic_write(APIC_LVTERR, apic_val); + apic_write(APIC_LVTPC, APIC_DM_NMI); } static int __kprobes @@ -1054,7 +1045,7 @@ void __init init_hw_perf_counters(void) pr_info("... counter mask: %016Lx\n", perf_counter_mask); - perf_counters_lapic_init(0); + perf_counters_lapic_init(); register_die_notifier(&perf_counter_nmi_notifier); } |